Architecture Overview#

mmap-guard is intentionally thin. The entire crate consists of four source files.

Module Structure#

lib.rs#

Crate root. Sets #![deny(clippy::undocumented_unsafe_blocks)] and re-exports the public API:

• FileData
• map_file
• load, load_stdin

file_data.rs#

Defines the FileData enum — the unified type returned by all public functions. Both variants (Mapped and Loaded) deref to &[u8].

map.rs#

Contains map_file() and the single unsafe block in the crate. Performs pre-flight checks (file exists, non-empty) before creating the memory mapping.

load.rs#

Convenience layer. load() routes "-" to load_stdin(Some(1 GiB)) for stdin, and delegates all other paths to map_file(). load_stdin(max_bytes) reads stdin in bounded chunks into a heap buffer and returns FileData::Loaded; passing None removes the cap.

Dependency Graph#

The crate has two runtime dependencies (memmap2 and fs4) and one dev-dependency (tempfile).